Influence of the sintering temperature on PTCR characteristics of porous Ba(Ti,Sb)O_3 ceramics

摘要

When appropriately doped, BaTiO_3 ceramics can be made semiconducting and they exhibit an anomalous sharp jump of resistivity at the Curie temperature [1-10]. This positive temperature coefficient of resistivity (PTCR) characteristic allows the manufacture of thermistors, level sensors, and self-regulated heaters [11-13]. The PTCR characteristics can be controlled by various factors such as dopant concentration, sintering temperature, sintering time and cooling rate, etc. [14,15]. These factors are further found to cause the change of the PTCR characteristics of BaTiO_3 ceramics through the variation of the room temperature resistivity and microstructure.